Hottest party 3 heads up (dance mat issue)

So I got the game for my gf, and the dance mat would not register steps during a song although it worked just fine in the menus. My Wii had firmware 4.2E installed, upgrading to 4.3E seems to have solved the issue.

You shouldn't have updated. That was a really stupid thing to do as far as safety and the possibility to softmod. The game wouldn't offer the update because it didn't need, or even come with 4.3. The fact that it started working again is a coincidence.

Don't ever suggest updating to 4.3 unless you want to make things worse (in which case you shouldn't be on here).

I spent more than 3 hours figuring out why the steps did not register.

1) I put the mat in every port (and I did that many a times) including connecting it before turning the wii on after connecting the mat, before connecting the mat, etc..
2) I swapped the power supply (you never know)
3) I removed my modchip (you never know)
4) I searched like crazy through all the menu's.
5) Googled for any issues that ppl may have mentioned.

And what did I get out of it? zilch. I'm well aware of the implications of upgrading and maybe I should've mentioned that for people that do not know. Sorry for that (I assumed the implications are quite well know atm).

And as soon as I upgraded, it worked. Now that can be a coincidence of course.

You are right, I was a bit harsh. I just didn't want people taking your post and assuming that updating was a good choice. Despite what we constantly tell people, newbies always seem to think updating will fix everything. I'm glad everything is working for you now.
The game you are playing has nothing to do with the System Menu, as games run off of IOS's. The only possible (and very unlikely) thing that could link updating and your mat working is a corrupt IOS. I don't even think the game would launch with a corrupt IOS, but I can't say for sure. When you update your Wii, it updates the System Menu (which blocks homebrew and bricks region changed Korean Wii's), IOS's, boot2, and a few other things. Since the game you have came out before 4.3, the IOS's you had worked.

While the issue has definitley sparked my interest, it's too late to test for anything. I'm still glad you got it working though.

No worries I'm not cross or anything, I really should have posted a warning anyway. For people that just play back ups of domestic games (I mean games belonging to the same region as their Wii) it doesn't really change much (I will bang my head into a wall if you tell me I broke that as I concluded upgrading to 4.3 was safe if you didn't care for playing out of region games!).
It seems Wasabi isn't going to fix the "play region free" issue. I also should catch up on reading whether chips still have a reason for existence.

Bizarre, since the game came out before 4.3, it should logically have worked. Perhaps the mats have changed somehow needing 4.3. But downgrading isn't possible if I read you correctly. I'm going to read the stuff in your signature. They seem to suggest upgrading to 4.3 does not cause irriversible damage for HomeBrew.

A last funny note: my aftermarked power supply jams my home plugs (they lose connection). I had to move my Wii's PSU to another socket. Oh well, it cost only 10 euro